Intravascular Coagulopathy In Discordant Xenotransplantation
Funder
National Health and Medical Research Council
Funding Amount
$447,750.00
Summary
The successful treatment of many conditions in which the relevant organ has failed completely and irreversibly is to replace that organ with a new one ie. to perform a transplant. It is well known that there are far fewer organs available for transplantation than the number needed. This means that for those conditions where a supportive treatment is available, eg. the artificial kidney, patients must be maintained by that method, however for other organs such as hearts, lungs and livers, there i ....The successful treatment of many conditions in which the relevant organ has failed completely and irreversibly is to replace that organ with a new one ie. to perform a transplant. It is well known that there are far fewer organs available for transplantation than the number needed. This means that for those conditions where a supportive treatment is available, eg. the artificial kidney, patients must be maintained by that method, however for other organs such as hearts, lungs and livers, there is no mechanical substitute. If these patients do not receive a transplant, they die. A solution to this problem is to use organs from animals. This is called xenotransplantation. The pig is the most suitable donor, however despite many similarities to humans which make it suitable, there are many differences which are still to be overcome before clinical application is possible. These differences are at a very fine molecular level and prevent the normal integration of the organ into the new recipient. The result is that the new organ is rejected within minutes. This process is called hyperacute rejection and by research into its mechanism it was found to be due to just a few differences. We and others have genetically modified pigs so that they have the human components and this has completely prevented this form of rejection. However,we have found a second barrier which causes a rejection response after a few days. It is now known that a major component of the cause of this second barrier is a few differences in the clotting system. We propose to make further genetic modifications which we think will prevent this rejection. This project proposes to examine various genetic modifications and test their effect in small animal models before going on to make and test pigs in which human anti-clotting genes have been inserted. . If we are successful, the possibility of replacing failed human organs with animal organs will be a step closer.Read moreRead less
Intravascular Coagulopathy In Discordant Xenotransplantation
Funder
National Health and Medical Research Council
Funding Amount
$227,036.00
Summary
The successful treatment of many conditions in which the relevant organ has failed completely and irreversibly, is to replace that organ with a new one ie. to perform a transplant. It is well known that there are far fewer organs available for transplantation than the number needed. This means that for those conditions where a supportive treatment is available, eg. the artificial kidney, patients must be maintained by that method, however for other organs such as hearts, lungs and livers, there ....The successful treatment of many conditions in which the relevant organ has failed completely and irreversibly, is to replace that organ with a new one ie. to perform a transplant. It is well known that there are far fewer organs available for transplantation than the number needed. This means that for those conditions where a supportive treatment is available, eg. the artificial kidney, patients must be maintained by that method, however for other organs such as hearts, lungs and livers, there is no mechanical substitute. If these patients do not receive a transplant, they die. A solution to this problem is to use organs from animals. This is called xenotransplantation. The pig is the most suitable donor, however despite many similarities to humans which make it suitable, there are many differences which are still to be overcome before we can use xenotransplants clinically. These differences are at a very fine molecular level and prevent the normal integration of the organ into the new recipient. The result is that the new organ is rejected within minutes. This process is called hyperacute rejection and by research into its mechanism it was found to be due to just a few differences. We and others have genetically modified pigs so that they have the human genes and this has completely prevented this form of rejection. However,we have found a second barrier which causes a rejection response after a few days. It is now known that a major component of the cause of this second barrier is a few differences in the clotting system. We propose to make further genetic modifications which we think will prevent this rejection. This project proposes to examine various genetic modifications and test their effect in small animal models before going on to make and test pigs into which human genes have been inserted. If we are successful, the possibility of replacing failed human organs with animal organs will be a step closer.Read moreRead less
The successful treatment of many conditions in which the relevant organ has failed completely and irreversibly is to replace the organ with a new one i.e. to perform a transplant. It is well known that there are far fewer organs available for transplantation than the number needed. This means that for those conditions where a supportive treatment is available, eg. the artificial kidney, patients must be maintained by that method, however for other organs such as hearts, lungs and livers, there i ....The successful treatment of many conditions in which the relevant organ has failed completely and irreversibly is to replace the organ with a new one i.e. to perform a transplant. It is well known that there are far fewer organs available for transplantation than the number needed. This means that for those conditions where a supportive treatment is available, eg. the artificial kidney, patients must be maintained by that method, however for other organs such as hearts, lungs and livers, there is no mechanical substitute. If these patients do not receive a transplant, they die. A solution to this problem is to use organs from animals. This is called xenotransplantation. The pig is the most suitable donor, however despite the many similarities to humans which make pigs suitable, there are many differences which are still to be overcome before we can use pig xenotransplants clinically. These differences are at a very fine molecular level and prevent the normal integration of the pig organ into the human recipient. It is well established that the single most important difference which causes this rejection is a sugar molecule like a blood group which pigs have but humans do not. This is called Gal. This is also present in most animal species and we have completely removed it from a strain of mice by genetic modification. Unfortunately it has not been possible to make this change in pigs. However, the genetically modified mice give us a test model to determine precisely how much and by what mechanisms the Gal antigen is responsible for the rejection process.Read moreRead less
Rapidly giving intravenous fluid to prevent or treat shock (fluid resuscitation) is one of the commonest treatments given to critically ill patients. Current guidelines recommend crystalloid solutions but it is unknown whether any particular crystalloid is better than others. This trial will determine whether the use of one of two crystalloid fluids, saline or PlasmaLyte, reduces the risk of organ injuries, such as kidney failure, and improves patients chances of surviving critically illness.
Many people with organ failure such as heart or kidney disease need a transplant to survive. In the case of kidney failure patients can be kept alive by the artificial kidney however this sort of mechanical traeatment is much less satisfactory than a transplant. Unfortunately most patients who would benefit from a transplant are unable to receive one beacuse of the shortage of living or cadaver donors. A possible solution to this shortage of organs for transplantation is to use animal organs. Pi ....Many people with organ failure such as heart or kidney disease need a transplant to survive. In the case of kidney failure patients can be kept alive by the artificial kidney however this sort of mechanical traeatment is much less satisfactory than a transplant. Unfortunately most patients who would benefit from a transplant are unable to receive one beacuse of the shortage of living or cadaver donors. A possible solution to this shortage of organs for transplantation is to use animal organs. Pigs are the most suitable animal donor. However, a pig-to-human organ is rejected immediatly because of the distance between the species. Over the last 10 years, we and others have been trying to understand which genetic differences are important. It is now clear that there are several important differences. One of these is a Blood Group like molecule in the pig that humans react with immediatly on transplantation. This is called the Gal molecule. We and others have been successful in removing the pig gene that makes this molecule. In addition we have added several human genes to pigs to prevent the early vigorous rejection which usually occurs. Organs from these genetically modified pigs have been tested by transplantation into baboons and monkeys. The transplants which used to be rejected within minutes, now survive for months. However, they organs are still rejected by a process which causes clotting in the transplanted organs. We now understand the mechanism andare making genetically modified pigs with human genes which regulate clotting of human blood. This project will test organs from these pigs by transplantation into baboons. We will also make a special strain of pigs in which all these genetic modifications are assembled. This involves the removal of one pig gene and the addition of 4 or 5 human genes. We think it is highly likely that this combination of genetic modifications will make this strain of pigs much more suitable as organ donors.Read moreRead less
Global Data Mapping And Evaluation Of Needs, Capacities And Benchmarks In Organ Donation And Transplantation: Informing Effective Local And International Health Policy To Better Meet The Needs Of Patients
Funder
National Health and Medical Research Council
Funding Amount
$318,575.00
Summary
Global shortages of donor organs limit the provision of reliable and equitable access to solid organ transplantation. As a result, many are excluded from waiting lists, others deteriorate whilst awaiting transplantation, and some seek to purchase the needed organ. Countries have a responsibility to provide transplantation services sufficient to meet population need. This project evaluates international data for key interventions that may impact on waitlisting, donation and transplant practices.
The Role And Function Of Macrophages In Cellular Xenograft Rejection
Funder
National Health and Medical Research Council
Funding Amount
$323,250.00
Summary
The long term objective of this project is to develop pig insulin secreting tissue as a treatment for type 1 diabetes. At present the main barrier to this is rejection. In paricular a type of white blood cell called macophages has an important role in causing the rejection seen in xenotransplantation (the transplantation of pig tissue into humans). Our reseach group has made novel observations which show that the way macrophages respond to a xenotransplant is different to the way it behaves to t ....The long term objective of this project is to develop pig insulin secreting tissue as a treatment for type 1 diabetes. At present the main barrier to this is rejection. In paricular a type of white blood cell called macophages has an important role in causing the rejection seen in xenotransplantation (the transplantation of pig tissue into humans). Our reseach group has made novel observations which show that the way macrophages respond to a xenotransplant is different to the way it behaves to the transplant of an organ from the same species. In the rejection of pig insulin secreting tissue, macrophages are able to respond in the absence of ongoing signals from T cells. This project aims to identify the receptors on macrophages that are responsible for this response. In particular those receptors that are important for facilitating the migration of macrophages to the transplant site and the receptors that allow macrophages to distinguish self from non-self will be analysed. Hopefully these receptors will be used as targets for new therapeutic agents that could be used to prevent the strong rejection response that occurs when pig insulin secreting tissue is transplanted into humans.Read moreRead less
The Dead Heart Project: When Is A 'dead' Heart Truly Dead?
Funder
National Health and Medical Research Council
Funding Amount
$1,672,053.00
Summary
Best practice treatment for end-stage heart failure is heart transplantation, yet donor heart availability is deficient and limited by current practices. Using extensive basic and clinical research approaches, this project aims to increase donor heart quantity and quality by profiling current and novel donor heart sources, and extending donor heart storage time and quality using a novel transport device and therapeutic agents - thus increasing the number of successful transplant recipients.
CAN PRIORITY ALLOCATION OF DECEASED DONOR KIDNEYS BASED ON EPLET AND BROAD HLA-ANTIGEN MATCHING IMPROVE KIDNEY TRANSPLANT POTENTIAL, REDUCES IMMUNOGENICITY AND IMPROVE HEALTH OUTCOMES IN INDIGENOUS KIDNEY TRANSPLANT CANDIDATES?
Funder
National Health and Medical Research Council
Funding Amount
$334,472.00
Summary
Although kidney transplantation has been shown to improve life expectancy in patients with chronic kidney disease (CKD), indigenous patients with CKD wait twice as long on the wait-list before transplant and have up to a 3-fold increased risk of rejection and infections resulting in graft loss and death respectively compared to non-indigenous patients. A better understanding of the immunological make-up of indigenous patients may help to reduce the risk of complications and improve survival.
The Role Of T-cell Apoptosis In Transplantation Tolerance
Funder
National Health and Medical Research Council
Funding Amount
$173,380.00
Summary
Organ transplantation is the treatment of choice for patients with end-stage heart, lung, liver or kidney failure and there have been spectacular improvements in the early success of these procedures. However the 10 year graft survival rate has not changed much in the past 15 years. One way of overcoming this problem is to manipulate the immune system so that the transplant is accepted indefinitely. This is called tolerance and it works by giving intense immunosuppression for a short period so t ....Organ transplantation is the treatment of choice for patients with end-stage heart, lung, liver or kidney failure and there have been spectacular improvements in the early success of these procedures. However the 10 year graft survival rate has not changed much in the past 15 years. One way of overcoming this problem is to manipulate the immune system so that the transplant is accepted indefinitely. This is called tolerance and it works by giving intense immunosuppression for a short period so that the transplant is accepted indefinitely without the need for long term immunosuppression. The immune mechanism responsible for this phenomenon is complex and is poorly understood. This project aims to study the early events in the immune system that leads to transplantation tolerance. In particular, factors involved in programmed cell death in white blood cells will be studied. Specially bred mice that have blocks in the cell death mechanisms will used to determine what effects these blocks have on the ability to induce tolerance. Other mice that have been genetically altered to allow their white cells to be tracked will be used to study the fate of these cells. If the mechanisms involved in tolerance induction are better understood, then it will be possible to design specific immunosuppressive drugs that will be used to produce tolerance in transplant patients.Read moreRead less